The invention relates to a weighing system that works on the principle of electromagnetic force compensation. The weighing system has two guide members that act as a parallel guide unit and connect a load support to a base region that is fixed to a housing. The weighing also has at least one transmission lever, which has lever arms of different lengths, supported on the base region. The weight force of a load to be weighed is transmitted by a load support, and the force is applied to the shorter lever arm of the transmission lever via a coupling element. The longer lever arm is secured to a coil that protrudes into an air gap of a permanent magnet system.
A weighing system as described above is disclosed in the German patent specification DE 32 43 350 C2. In the weighing system described in documented 32 43 350 C2, the transmission lever, the permanent magnet system and the coil are located in an area within the parallel guide unit (i.e., within the base region, the load support and the two guide members). However, if this system is made narrower, the length of the transmission lever and the space available for the permanent magnet system would be very limiting.
A similar system is disclosed in the European publication EP 0 291 258 A2. In EP 0 291 258 A2, the base region of the weighing system is configured with two subregions that are interconnected by spacers. However, this configuration would also limit the length of the lever and the space available for the permanent magnet system.
To avoid the drawback of the limited length of the transmission lever, the German laid-open publication DE 100 15 311 A1 discloses a design in which the transmission lever is guided along one side of the base region and an arrangement in which the permanent magnet system and the coil are outside the parallel guide unit. This allows for a transmission lever with relatively greater length, but the lateral transmission lever substantially increases the width of the weighing system.
Therefore, with the above design, the width of the permanent magnet system is very limited if a plurality of narrow weighing systems are tightly spaced side by side in a row. For example, if the weighing systems are arranged side by side with a lateral distance of 15 mm, the width of the permanent magnet system cannot exceed 15 mm. For cylindrical permanent magnet systems, this means that the diameter cannot exceed 15 mm. As a result, the load bearing capacity of such narrow weighing systems is severely limited.